The present invention relates to the control of fluid flow in microfluidic devices.
There has been a growing interest in the manufacture and use of microfluidic systems for acquiring chemical and biological information. In particular, when conducted in microfluidic volumes, complicated biochemical reactions may be carried out using very small volumes of liquid. Among other benefits, microfluidic systems increase the response time of reactions, minimize sample volume, and lower reagent consumption. When volatile or hazardous materials are used or generated, performing reactions in microfluidic volumes also enhances safety and reduces disposal quantities.
Microfluidic devices are becoming more important in a wide variety of fields from medical diagnostics and analytical chemistry to genomic and proteomic analysis. It is difficult or impossible to perform complex fluid handling procedures using currently available microfluidic systems. For example, controlling the direction of fluid flow within a device, or achieving complex fluid flow patterns inside microfluidic devices is difficult to achieve using current technology. As microfluidic systems become more widely used, the tasks that they will perform will become increasingly complex.
There is a need in the field of microfluidics to provide microfluidic systems with components that can control fluid flow within a microfluidic device and, more particularly, for devices capable of providing uni-directional fluid flow. It would be particularly desirable for such a device to be able to be prototyped and modified quickly so as to enable rapid device optimization. These and other needs and desirable aspects are addressed herein.
In one separate aspect of the invention, a microfluidic fluid control device includes a first or inlet channel having a valve seat disposed therein at a valve region and a second or outlet channel with a flexible membrane separating the first channel and the second channel. The flexible membrane has an aperture aligned with the valve seat at a valve region. The aperture can be smaller than a seating surface of the valve seat. The flexible membrane can form a seal with the valve seat.
The microfluidic fluid control devices of the invention can be constructed to allow fluid flow in one direction, but substantially block fluid flow in the opposing direction. A microfluidic fluid control device may also include a second valve seat disposed in the second channel.
In another separate aspect of the invention, a microfluidic pump includes a first fluid control device and a second fluid control device as summarized above, wherein the first and second control devices are oriented such that fluid can flow in only one direction through the device. The microfluidic pump further includes an expandable reservoir separating the first fluid control device and the second fluid control device. The pump may further include an actuator for moving the deformable membrane.
In another aspect, any of the foregoing separate aspects may be combined for additional advantage.
These and other aspects and advantages of the present invention will become apparent from the following detailed description of the preferred embodiments taken in conjunction with the figures.